pencilfishes

Pencilfishes are small, slender freshwater fish belonging to the family Nannostomidae. They are native to the Amazon and Orinoco river basins in South America. The name "pencilfish" comes from their elongated, torpedo-shaped bodies, which resemble a pencil. They are a popular choice for aquarium hobbyists due to their peaceful nature and attractive colors.

There are over 40 known species of pencilfish, with the most common in the aquarium trade being the Dwarf Pencilfish (Nannostomus marginatus), Coral Red Pencilfish (Nannostomus eques), and Beckford's Pencilfish (Nannostomus beckfordi). Coloration varies widely among species, often featuring horizontal stripes or iridescent patches. Many pencilfish exhibit a unique behavior of resting head-downward in aquatic plants, which is thought to help them ambush small prey.

Pencilfishes are omnivores, feeding on small insects, larvae, and plant matter in the wild. In captivity, they readily accept flake foods, frozen foods like brine shrimp and daphnia, and small live foods. They are schooling fish and are best kept in groups of six or more to reduce stress and encourage natural behaviors. A planted aquarium with a moderate current and subdued lighting is ideal for pencilfish. They are generally hardy but can be sensitive to poor water conditions.